Wave energy compound refractors



Oct. 30, 1956 W. E. KOCK WAVE ENERGY COMPOUND REFRACTORS Filed Oct. 19,1951 FIG.

INVENTOR M. E. KOCK AT ORNEV United States Patent WAVE ENERGY COMFOUNDREFRACTORS Winston E. Kock, Basking Ridge, N. J., assignor to BellTelephone Laboratories, Incorporated, New York, N. Y., a corporation ofNew York Application October 19, 1951, Serial No. 252,029

Claims. (Cl. 343-909) This invention relates to compound phase-advancetype refractors for use in wave energy transmission systems. Moreparticularly, it relates to spaced parallel reflecting plate type waveenergy refractors combining prismatic and focusing effects.

This application is a division of my copending application Serial No.68,542, filed December 31, 1948, which matured into United States Patent2,599,763, granted June 10, 1952, for Directive Antenna Systems, which,in turn, is a continuation-in-part of my application for Radio RelaySystems, Serial No. 5,952, filed February 3, 1948, which last-mentionedapplication matured into United States Patent 2,530,826, grantedNovember 21, 1950.

Phase-advance type refractors and lenses for high frequencyelectromagnetic wave energy are disclosed and claimed in my copendingapplications No, 642,722, which matured into United States Patent2,588,249, granted March 4, 1952, and 642,723, which matured into UnitedStates Patent 2,736,894, granted February 28, 1956, respectively, bothof which applications were filed on January 22, 1946. It is furtherdisclosed and claimed in my copending application Serial No. 660,337,filed April 8, 1946, which matured into United States Patent 2,603,749,granted July 15, 1952, that wire curtains or grids of conductive memberscan replace the plane conductive sheets employed in the devices of thefirst-mentioned two applications.

The general principle is that the spaced members or partitionscomprising the refractor and/or lens (sheets, wire curtains, or grids)must be capable of reflecting substantially all wave energy of thewavelengths with which they are to be employed. On the other hand, onlysufficient mechanical rigidity to maintain the partitions in theirrespective proper positions is required. Indeed, for very high frequencyelectromagnetic waves, the partitions can be, for example, of extremelythin copper foil and the required mechanical rigidity can be provided byaffixing the foil to suitable surfaces of dielectric material such aspolyfoam, or the like. Alternatively, the dielectric material can haveits appropriate surfaces coated with a thin layer of highly conductivepaint or the like. The blocks are preferably of the appropriatethickness and dielectric constant to serve as the dielectric channelsbetween the conductive surfaces. Polyfoam, since it has very nearly thesame dielectric constant as air, is frequently employed in blocks ofappropriate dimensions to serve as spacers and supports for theconductive members or partitions in phase advance type refractors andlenses, and is, obviously, readily adaptable for use in devices of theinvention designed to be used with high frequency electromagnetic waveenergy.

It is a principal object of the present invention to obtain a compact,easily constructed, wave energy refractor comprising the combination ina unitary structure of a phase-advance type prism with one or severalphaseadvance type lenses.

Another object is to provide a novel structure for use "ice in radiosystems which will alter the direction of a plane wave front wave, andconvert it into a curved front wave having a predetermined focalposition.

A further object is to provide a novel structure for use in radiosystems which will convert a curved front wave into a plane front waveand alter the direction of the plane front wave.

Other and further objects will become apparent during the course of thefollowing detailed description of illustrative embodiments of theinvention and from the appended claims.

The principles of the invention will be more readily understood from thefollowing description of two simple embodiments of the invention andfrom the accompanying drawings, in which:

Fig. 1 is a perspective view of a compound phaseadvance type wave energyrefractor constructed in accordance with the principles of the inventionand comprising a prism section and a lens section; and

Figs. 2 and 3 are perspective and side views, respectively, of anothercompound phase-advance type wave energy refractor constructed inaccordance with the principles of the invention and comprising a prismsection assembled between two lens sections.

In more detail, Figs. 1 and 2 illustrate compound phaseadvance type,wave energy refractors which are, by way of example, especially suitablefor use in radio relay systems such as that disclosed in myabove-mentioned patent, 2,530,826. The refractor 40 of Fig. 1 comprisesa focusing section or plane-concave lens 41, such as that disclosed andclaimed in my copending application Serial No. 642,723, filed January22, 1946 (United States Patent 2,736,894), and a non-focusing or prismsection 42, such as that disclosed in my copending application SerialNo. 642,722, also filed January 22, 1946 (United States Patent2,588,249). Each section comprises a plurality of parallel spaced plates43, which for radio wave energy can be metallic sheets or grids ofmetallic members (i. e., wire curtains as disclosed in my copendingapplication Serial No. 660,337, filed April 8, 1946, which matured intoUnited States Patent 2,603,749, granted July 15, 1952). Inasmuch as theshape of lens 41 is plano-concave, the lens portion of each plate 43inherently has oppositely disposed plane edge boundaries that form astraight line on the plane side of the lens and a curved concave arc onthe concave side of the lens. Similarly, the prism portion of each plate43 inherently has oppositely disposed plane edge boundaries formingstraight lines that intersect each other at an angle. Each plate iscommon to both sections so that, while, from an electrical or refractivestandpoint, the two sections can be considered as being distinct, thetwo sections are mechanically or physically integrated into a unitarystructure. Thus the plane shape of a unitary plate 43 has one straightline boundary and one curved concave arcuate boundary oppositelydisposed from the straight line boundary. In view of the shape of theprism, an extension of the straight line boundary forms an angle withthe extension of the chord joining the ends of the arcuate boundary. Theplates are, for the embodiments illustrated in the drawing, held inposition by the wooden members 44. In the embodiment of Fig. 2, theprism section 62 is, as indicated by the dash lines, included betweentwo thin plano-concave lenses 65 and 66, as more clearly shown in Fig.3. Thus both oppositely disposed edge boundaries form curved concavearcs the chords of which intersect at an angle.

In operation, in Fig, 1, the lens section 41 functions, for example, toconvert the circular front wave 47 originating at the line focus 3 to aplane front wave having a propagation direction as indicated by thearrow 48 and the prism section 42 functions to change the direction ofpropagation from the direction indicated by the arrow 48 to thedirection indicated by the arrow 49. Similarly, in the system of Figs. 2and 3, the lens section 65 operates to convert the circular wave front47 originating at the left focal line 3 to a plane wave front and theright lens section 66 changes the plane front to a circular frontconverging on the right focal line 3. The intermediate prism section 62changes the propagation direction from the mean direction 50 incoming tolens 65 to the mean direction 51 outgoing from lens 66.

Although the invention has been explained in connection with certainspecific embodiments, it is to be understood that it is not to belimited to the described embodiments since numerous and varied otherarrangements clearly within the spirit and scope of the invention, can,obviously, be readily devised by those skilled in the art.

What is claimed is:

1. A compound phase-advance type of wave energy refractor for highfrequency wave energy, comprising a plurality of like plane membersspaced parallel to each other, adjacent members being separated by aninterval exceeding one-half wavelength of the lowest frequency of thewave energy with which the refractor is to be used, each member being asubstantially complete reflector of the wave energy with which it is tobe employed, the plane of each member having two principal boundariesoppositely disposed to each other, one of said boundaries being astraight line, the other of said boundaries being a concave arc, anextension of said straight line boundary forming an angle with anextension of a chord joining the ends of said arcuate boundary.

2. A compound phase-advance type wave energy refractor for highfrequency electromagnetic waves which comprises a plurality of like,parallel, plane conductive members, consecutive ones of said membersbeing spaced apart a distance which is greater than one-half Wavelengthof the lowest frequency with which the refractor is to be used, theplane of each of said members having two principal curved edgesoppositely disposed to each other, the extension of a chord joining theends of one of said curved edges forming an angle with the extension ofa chord joining the ends of the other of said curved edges.

3. The structure of claim 2 wherein the said curved edges are concave.

4. A compound refractor for high frequency wave energy comprising aplurality of like, equally spaced, parallel plane members, each of saidmembers being an efiicient reflector of said wave energy, the plane ofeach of said members having two principal boundaries oppositely disposedto each other, both of said boundaries being a concave arc, theextension of a chord joining the .ends of one of said arcs forming anangle with the extension of a chord joining the ends of other of saidarcs whereby said overall structure can impress both focusing andprismatic directional effects upon the Wave energy directed through saidrefractor.

5. A compound refractor for high frequency wave energy comprising aplurality of like, equally-spaced, parallel, plane members, each of saidmembers being an efiicient reflector of said wave energy, the plane ofeach of said members having two principal boundaries oppositely disposedto each other, at least one of said boundaries being a concave arc, theextension of a chord joining the ends of said concave are forming anangle with an extension of a straight line joining the ends of the otherof said boundaries whereby said over-all structure can impress bothfocusing and prismatic directional effects upon said wave energydirected through said refractor.

References Cited in the file of this patent OTHER REFERENCESElectronics, page 101, March 1946.

